As safety concerns for rail systems become an increasingly important public issue, a need has arisen for implementing positive train control (PTC), which incorporates equipment onboard (and offboard) trains for train collision avoidance and line speed enforcement. As trains move at high speeds, it may be important to detect potential collisions well in advance, so that trains can be slowed down to prevent collisions. These systems may use technology to identify other trains on the rail system as well as their relative speeds for collision prevention. However, proposed PTC systems may require substantial infrastructure changes, and the estimated multi-billion dollar infrastructure costs may pose a serious obstacle for implementing PTC.
One system for implementing PTC is described in U.S. Pat. No. 7,222,003 B2 (“the '003 patent”). The '003 patent is directed to a method and computer program product for monitoring the integrity of a railroad train and determining passage of the train relative to a plurality of virtual blocks defined by wireless transmissions along a section of track over which the train travels. The virtual blocks provide safeguards for the travel of the train relative to other trains on the section of the track when there is a shared use of the section of track.
The system provided by the '003 patent is subject to a number of possible drawbacks. For example, this system includes a centralized traffic control system that a train must communicate with to determine the presence or absence of a virtual block. Furthermore, this system monitors virtual blocks, which are defined portions of the railway. Such a system may be unduly complex for determining a potential collision threat and may require monitoring of the relative location of the locomotive to potential threats as well as those locations relative to the location of the virtual block. Thus, a less complex collision threat detection system may be desired.
The presently disclosed systems and methods are directed to overcoming one or more of the problems set forth above and/or other problems in the art.